The principle of the electrospinning technique is to provide a high-voltage electric field in an area which threads pass through after jetted from a spinning device, and when jetted from a spinneret of the spinning device, the threads are electrically charged by the spinning process; therefore, because of the electric property of the threads, the effect of the electric field on the threads results in finer threads. For the present techniques, the diameter of the threads can be as small as one hundred nanometers.
Please refer to FIG. 1, which shows a schematic diagram of an electrospinning equipment in the prior art. An electrospinning equipment 1 includes a collector 14 and a power supply PS electrically connected to a material supply 10, wherein the material supply 10 faces the collector 14; namely the normal to the plane of the collector 14 is parallel to the direction in which the material supply 10 supplies a material, and a diffusion electric field ef1 is generated therebetween. Besides, the material supply 10 usually is a capillary and has a spinneret 12 which a polymer solution FS is jetted from to form a thread F1. Ideally the thread F1 extends straightly toward the collector 14, but actually the thread F1 fluctuates transversely resulting from the electric charge repulsion inside the thread F1, and hence the thread F1 is usually deposited on the collector 14 disorderly. Therefore, the electrospinning technique is mostly applied to nonwoven manufacturing for its disordered arranging feature. On the contrary, it is difficult to roll the thread F1 on a roller used in other techniques, and rearranging the thread F1 and rolling it on the roller is unrealistic since it is time-consuming.
Please refer to FIG. 2, which shows a schematic diagram of another electrospinning equipment in the prior art. The electrospinning equipment comprises a first power supply PS1 electrically connected to a material supply 10 usually being a capillary and having a spinneret 12, a second power supply PS2 electrically connected to a circle 2, and a third power supply PS3 electrically connected to a collector 14. Compared with the electrospinning equipment 1 shown in FIG. 1, the one shown in FIG. 2 is to configure the circle 2 between the spinneret 12 and the collector 14 for forming stable threads without transverse fluctuation by providing an electric potential for the circle 2 through the second power supply PS2, wherein the electric potential of the circle 2 is higher than that of the collector 14 but lower than that of the material supply 10. Therefore, an upper electric field ef2a is generated between the circle 2 and the spinneret 12, and a lower electric field ef2b is generated between the circle 2 and the collector 14. A former thread F2a jetted from the spinneret 12 and passing through the upper electric field ef2a is in a straight state without transverse fluctuation. However, after passing through the circle 2 and reaching the area between the circle 2 and the collector 14, the former thread F2a becomes a latter thread F2b, and a diffusion is formed again. Nevertheless, the range of the transverse fluctuation of the latter thread F2b is smaller than that of the thread F1 shown in FIG. 1. Nevertheless, the range is not small enough to rearrange the thread F2a as a long straight state in a simple way.
Accordingly, in the field of electrospinning technique, a new structure is necessary for the thread to be deposited on the collector stably without transverse fluctuation.